The present invention relates to an apparatus for detecting defects on a bottle mouth having a screw thread, such as stones, voids, breakages, cracks, foreign materials stuck to the bottle mouth, stains or deformed threads.
Glass bottles used for filling with liquor, refreshing drink, food or the like must be inspected as to whether there is any defect irrespective of whether they are new ones just manufactured by a bottle maker or old ones being recirculated. Portions of a bottle to be inspected include its body, bottom, mouth with a screw thread. If there is any defect at the bottle mouth, sealing of the bottle becomes insufficient and hence resulting in a possible problem of food sanitation. Therefore, bottles with such defect must be rejected.
It is difficult, however, to inspect bottle mouths because of their complicated shape and various thread patterns. It is also difficult to distinguish a normal thread configuration from a defect. Because of the above difficulties, in spite of a necessity of inspecting bottle mouths, a bottle mouth inspecting apparatus available in practice has not been provided.